Question: The perimeter of a rectangle is $20$ centimeters. The length is $6$ centimeters. What is the area of the rectangle?
Solution: Perimeter is the distance around a closed figure. We can find the perimeter of a shape by adding all the side lengths. The perimeter is $20}\text{ cm}$ and the length is ${6}\text{ cm}$. $6\text{ cm}$ $6\text{ cm}$ $\text{Perimeter}= 20\text{ centimeters}\,$ $\,$ $\,$ $\begin{aligned} P} &= {l} + {w} + {l} + {w}\\\\ 20} &= {6} + {w} + {6} + {w} \\\\ 20} &= {w} + {w} + {12}\\\\ 8&= {w} + {w} \end{aligned}$ What number can we add twice to get $8$ ? The width of the rectangle is ${4}$ centimeters. Now, we can find the area. $\begin{aligned} \text{Area} &= {\text{length}} \times {\text{width}}\\\\ &= {6} \times {4}\\\\ &= 24\text{ square centimeters} \end{aligned}$ The area of the rectangle is $24$ square centimeters.